14-03-2023: Electronics 9

Date: Tuesday, March 14 2023

Location: Pi

Time: 10:45 - 12:30

color coded resistors

Question of the day

Which type of device can we use as controller and how do we model its performance?

Knowledge Test

Press the button(s) below to test your knowledge and understanding of the topics covered this lecture.


Homework previous lecture

Operational Amplifiers: types and modeling techniques

Types of operational amplifiers

The operational amplifier was invented as a controller for analog computers. The “standard” operational amplifier has a floating (differential) voltage input and a grounded voltage output. Nowadays, different types of operational amplifiers exists.

Presentation

The presentation “OpAmps: types” briefly summarizes the historical development of operational amplifiers and lists the properties of the different types.

Presentation in parts

OpAmps: types (parts)

Video

Opamp Types (8:04)

Study

Chapter 8.1

Modeling of operational amplifiers

Manufacturers of operational amplifiers usually provide macro-models for SPICE simulation. Such models, however, do not provide design information.

Presentation

The presentation “Operational Amplifiers: modeling” presents techniques for modeling of specific behavioral apsects, for both SPICE simulators and for SLiCAP.

Presentation in parts

Operational Amplifiers: modeling (parts)

Videos

  1. Modeling of the behavior of operational amplifiers (10:37)

  2. Modeling of the small-signal dynamic behavior of operational amplifiers (5:17)

  3. (LT)spice nullor model (3:12)

  4. A programmable noise source for (LT)spice (3:47)

  5. Opamp model derived from datasheet (21:54)

Study

Chapter 8.3

Operational Amplifiers: negative feedback amplifiers with OpAmps as controller

Feedback amplifiers with standard operational amplifiers as controllers

Operational amplifiers are intended to be used as controllers in negative feedback amplifiers. Standard operational (voltage) amplifiers use both supply terminals as return path of the output port. This complicates the implementation of output current sensing.

Presentation

The presentation “Feedback configurations with operational amplifiers” illustrates this and presents alternative current sensing techniques.

Presentation in parts

Feedback configurations with operational amplifiers (parts)

Video

Feedback amplifier configurations with operational amplifiers (6:37)

Study

Chapter 8.4.1

Synthesis of multiple-controller feedback configurations

If a feedback amplifier comprises multiple controllers, alternative configurations that all have the same ideal gain can be found by pairing the nullators and norators differently.

Presentation

The presentation “Multiple-nullor circuit synthesis” demonstrates this technique for an active-feedback inverting voltage amplifier.

Presentation in parts

Multiple-nullor circuit synthesis (parts)

Video

EE3C11 lecture 9: Multiple nullor Circuit Synthesis

Study

Chapter 7.6.1

Homework

Homework 7: Create a small-signal model for the TLV4111

This model must include:

  • Frequency behavior of the voltage gain

  • Frequency behavior of the input impedance

  • Frequency behavior of the output impedance (needs chapter 11)

  • Input voltage noise spectral density

  • Input current noise spectral density